I believe it's been mentioned that Gunn, Illyria, and Connor will be mentioned in the run. I don't see how Angel becoming Twilight "ruined" his character. We still don't really know (at least to my knowledge) how and why he become Twilight. We know the motivation. Angel's actions and consequences are all part of the characters ongoing theme of redemption in the long run and well what was established on both shows.
It's way to early to judge what will be addressed in the comics, since you know, they've not even debuted yet.